Hi, I need some help with stopping an oil leak on my N600. The leak
seems to be located just under the intake manifold above the head
gasket. Oil can be seen along the head casting near the base of a
6mm bolt that connects the head and cylinder barrel. I am a bit
confused by the Honda Repair Manual (Blue Book) which states that the
Flange cap nuts should be on the inlet side to prevent oil leaking.
(Page 4-28). This is the where I installed the flange cap nuts, but
my leak is still occurring. What does the group know about these
flange nut bolts?
I am also confused by the use of rubber spacers on the valve
rockers. The Manual states that the 600 cc engines used springs on
the outside of both the intake and exhaust sides. I have springs
for the intake and spacers for the exhaust. Which is correct?
Thanks, Joel
oil leaks
Re: oil leaks
Joel,
The problem with the Blue Manual is it was printed before the
Synchromesh cars were produced. The early engines had Exposed Studs
in the rear of the engine. The casting for the cylinders was such
that the 2 center rear studs were visible this is why they used the 2
small o-rings on the center studs of the early sedans. The cap nut in
turn would keep oil from leaking past the threads on the 2 center
rear studs. The later engines corrected the design and dropped the 2
orings.
I have had problems in the past bottoming out the cap nuts on the
studs, so on every engine I build since the early 1980's I place a
flat washer under the cap nuts also to make sure of a good seal.
Honda does not say to put a washer under the caps nuts, but just do
it anyway.
The correct placement of springs and plugs: The 2 long springs go on
exhaust rocker shafts between rocker and housing which is visible
under the rocker lid, then 2 rubber plugs go in after the shafts on
the exhaust sides. Only the Intakes use the small springs and only on
the outside ends of the intake shafts.
Oil Leaking: I would have to ask if you used genuine Honda gaskets
when assembling the engine and if all surfaces were cleaned? If the
engine was assembled with regular paper gaskets you will have
problems as they absorb oil and you will lose the head torque, oil
will leak everywhere. If you can't get OEM gaskets, I have some super
duper Klinger-Sil C4500 material that is carbon-fibre and is rated at
900 degrees (I believe). I had to buy a 5'x5' square sheet of the
stuff and will sell it at cost of $5.00 square foot. I use Honda-Bond
4 on all my gaskets (except the cam bearing gaskets) to prevent oil
leaks.
Miles
The problem with the Blue Manual is it was printed before the
Synchromesh cars were produced. The early engines had Exposed Studs
in the rear of the engine. The casting for the cylinders was such
that the 2 center rear studs were visible this is why they used the 2
small o-rings on the center studs of the early sedans. The cap nut in
turn would keep oil from leaking past the threads on the 2 center
rear studs. The later engines corrected the design and dropped the 2
orings.
I have had problems in the past bottoming out the cap nuts on the
studs, so on every engine I build since the early 1980's I place a
flat washer under the cap nuts also to make sure of a good seal.
Honda does not say to put a washer under the caps nuts, but just do
it anyway.
The correct placement of springs and plugs: The 2 long springs go on
exhaust rocker shafts between rocker and housing which is visible
under the rocker lid, then 2 rubber plugs go in after the shafts on
the exhaust sides. Only the Intakes use the small springs and only on
the outside ends of the intake shafts.
Oil Leaking: I would have to ask if you used genuine Honda gaskets
when assembling the engine and if all surfaces were cleaned? If the
engine was assembled with regular paper gaskets you will have
problems as they absorb oil and you will lose the head torque, oil
will leak everywhere. If you can't get OEM gaskets, I have some super
duper Klinger-Sil C4500 material that is carbon-fibre and is rated at
900 degrees (I believe). I had to buy a 5'x5' square sheet of the
stuff and will sell it at cost of $5.00 square foot. I use Honda-Bond
4 on all my gaskets (except the cam bearing gaskets) to prevent oil
leaks.
Miles
-
stevecrawford47
- Posts: 1
- Joined: Wed Dec 07, 2005 1:27 pm
Re: oil leaks
--- In 2cylinderhondas@yahoogroups.com, "Miles Chappell
" wrote:
Thanks Miles,
I will place a flat washer under the acorn nuts and retorque the
nuts. The gasket surfaces were cleaned. I used a fiber based gasket
material from NAPA auto parts. (better than paper, but not as good
as you have). I will buy some material from you, but won't have
time to cut gaskets until Spring Break.
I appreciate your taking time to clear up my confusion regarding
rocker springs and plugs :-)
Joel
" wrote:
Thanks Miles,
I will place a flat washer under the acorn nuts and retorque the
nuts. The gasket surfaces were cleaned. I used a fiber based gasket
material from NAPA auto parts. (better than paper, but not as good
as you have). I will buy some material from you, but won't have
time to cut gaskets until Spring Break.
I appreciate your taking time to clear up my confusion regarding
rocker springs and plugs :-)
Joel
> The problem with the Blue Manual is it was printed before the
> Synchromesh cars were produced. The early engines had Exposed Studs
> in the rear of the engine. The casting for the cylinders was such
> that the 2 center rear studs were visible this is why they used the 2
> small o-rings on the center studs of the early sedans. The cap nut in
> turn would keep oil from leaking past the threads on the 2 center
> rear studs. The later engines corrected the design and dropped the 2
> orings.
> I have had problems in the past bottoming out the cap nuts on the
> studs, so on every engine I build since the early 1980's I place a
> flat washer under the cap nuts also to make sure of a good seal.
> Honda does not say to put a washer under the caps nuts, but just do
> it anyway.
> The correct placement of springs and plugs: The 2 long springs go on
> exhaust rocker shafts between rocker and housing which is visible
> under the rocker lid, then 2 rubber plugs go in after the shafts on
> the exhaust sides. Only the Intakes use the small springs and only on
> the outside ends of the intake shafts.
> Oil Leaking: I would have to ask if you used genuine Honda gaskets
> when assembling the engine and if all surfaces were cleaned? If the
> engine was assembled with regular paper gaskets you will have
> problems as they absorb oil and you will lose the head torque, oil
> will leak everywhere. If you can't get OEM gaskets, I have some super
> duper Klinger-Sil C4500 material that is carbon-fibre and is rated at
> 900 degrees (I believe). I had to buy a 5'x5' square sheet of the
> stuff and will sell it at cost of $5.00 square foot. I use Honda- Bond
> 4 on all my gaskets (except the cam bearing gaskets) to prevent oil
> leaks.
> Miles
> --- In
2cylinderhondas@yahoogroups.com
, "Joel Sturm
> " wrote:
> > Hi, I need some help with stopping an oil leak on my N600. The
> leak
> > seems to be located just under the intake manifold above the head
> > gasket. Oil can be seen along the head casting near the base of
> a
> > 6mm bolt that connects the head and cylinder barrel. I am a bit
> > confused by the Honda Repair Manual (Blue Book) which states that
> the
> > Flange cap nuts should be on the inlet side to prevent oil
> leaking.
> > (Page 4-28). This is the where I installed the flange cap nuts, but
> > my leak is still occurring. What does the group know about these
> > flange nut bolts?
> > I am also confused by the use of rubber spacers on the valve
> > rockers. The Manual states that the 600 cc engines used springs on
> > the outside of both the intake and exhaust sides. I have springs
> > for the intake and spacers for the exhaust. Which is correct?
> > Thanks, Joel
-
dealadayray
- Posts: 1
- Joined: Sun Aug 18, 2002 12:08 am
Re: oil leaks
Yea Know Miles, you brought up an interesting point, all the head nuts
have washers but also are open which allows them to torque past the stretch
of the stud. I too was looking for a reason the rear area of the head was
always developing a leak after several thousand miles. Not only the stretch
of the studs makes it harder to torque but the fact that every time I
rebuild a head it's surfaced lending to the loss of another 3 to 5 thousands
coupled with possible over torquing which can cause warping. But all this
aside we can torque the cap nut only so far while the other nuts will still
pull the head down enough to seal but also allows the rear two studs to
lift. My torque wrench only shows pounds feet applied, not the stretch of
the stud. A washer and cap nut would do the trick, unless the stud has
stretched past this limit, rather the width of the washer, also.
Speaking over torquing, this does cause the cam box to warp on the
outside edges. The 6mm bolts on the four corners will curve up and leak
when the head studs are over torqued. Torquing the four corners to 120 inch
pounds before completing the final torque on the studs will maintain even
pressure across the cam box to head area. And the gasket for the cam box
should be 1/32 thick, thinner material will work but the surface and torque
requirements must be more critical.
Bill
have washers but also are open which allows them to torque past the stretch
of the stud. I too was looking for a reason the rear area of the head was
always developing a leak after several thousand miles. Not only the stretch
of the studs makes it harder to torque but the fact that every time I
rebuild a head it's surfaced lending to the loss of another 3 to 5 thousands
coupled with possible over torquing which can cause warping. But all this
aside we can torque the cap nut only so far while the other nuts will still
pull the head down enough to seal but also allows the rear two studs to
lift. My torque wrench only shows pounds feet applied, not the stretch of
the stud. A washer and cap nut would do the trick, unless the stud has
stretched past this limit, rather the width of the washer, also.
Speaking over torquing, this does cause the cam box to warp on the
outside edges. The 6mm bolts on the four corners will curve up and leak
when the head studs are over torqued. Torquing the four corners to 120 inch
pounds before completing the final torque on the studs will maintain even
pressure across the cam box to head area. And the gasket for the cam box
should be 1/32 thick, thinner material will work but the surface and torque
requirements must be more critical.
Bill
oil leaks
I think I have figured out why the cam housing requires two cap nuts
on bolts #12 and #14. Those bolts do not fit down blind holes. They
protrude outside of the cooling fins of the cylinder barrel.
Therefore, any oil which gets past those cap nuts runs down the
outside of the bolts and out of the engine at the cylinder barrel.
There needs to be a complete seal at the top of the bolts to keep the
oil from doing this.
Also, When I reassemble the engine, will I need a new head gasket?
And should I use gasket dressing on the head gasket as I would with
the Cylinder housing gasket? Let me know your thoughts.
Joel
on bolts #12 and #14. Those bolts do not fit down blind holes. They
protrude outside of the cooling fins of the cylinder barrel.
Therefore, any oil which gets past those cap nuts runs down the
outside of the bolts and out of the engine at the cylinder barrel.
There needs to be a complete seal at the top of the bolts to keep the
oil from doing this.
Also, When I reassemble the engine, will I need a new head gasket?
And should I use gasket dressing on the head gasket as I would with
the Cylinder housing gasket? Let me know your thoughts.
Joel
Re: oil leaks
Your right about the bolts. The cap heads are to prevent leaks as you described.
Yes, you do need a new head gasket, Honda head gaskets are graphite and glue coated, and will leak if reused. No dressing is required because of this.
Wayne
Honda top tech
Ase master tech
Yes, you do need a new head gasket, Honda head gaskets are graphite and glue coated, and will leak if reused. No dressing is required because of this.
Wayne
Honda top tech
Ase master tech
-
dealadayray
- Posts: 1
- Joined: Sun Aug 18, 2002 12:08 am
Re: oil leaks
Hay Joe;
That is great, but if you have a early cylinder head you still need 10mm
O rings at the base of the same studs. You will know this by turning over
the cylinder and noting that it is not flat at the bottom of these two stud
holes. The later cylinders were flat, giving it a good clean surface to
mate to at the base of the cylinder. You should not need any sealant with
your head gasket.
Bill
That is great, but if you have a early cylinder head you still need 10mm
O rings at the base of the same studs. You will know this by turning over
the cylinder and noting that it is not flat at the bottom of these two stud
holes. The later cylinders were flat, giving it a good clean surface to
mate to at the base of the cylinder. You should not need any sealant with
your head gasket.
Bill
Re: oil leaks
Thanks Wayne,
Do you have a source for the head gasket?
Joel
Do you have a source for the head gasket?
Joel
--- In
2cylinderhondas@yahoogroups.com
, bxstine@a... wrote:
> Your right about the bolts. The cap heads are to prevent leaks as
you
> described.
> Yes, you do need a new head gasket, Honda head gaskets are graphite
and glue
> coated, and will leak if reused. No dressing is required because
of this.
> Wayne
> Honda top tech
> Ase master tech